The present invention generally relates to optical semiconductor microelectronics, and more particularly to epitaxial crystal multilayer structures and a manufacturing method thereof. The invention also relates to semiconductor light-emitting devices with enhanced light emission output intensity.
In recent years, red light-emitting diodes (LEDs) have become more widely used in the manufacture of electronic equipment. Several types of LEDs have been developed to date. A double-heterostructure LED is one example. A rear-surface reflection LED is another example. These LEDs come with enhanced luminance, and hence offer extended usability and applicability, such as for use with indoor lamps and display devices, as well as outdoor display devices.
However, in spite of the foregoing advances in this technology, it is also true that there are continuous demands for a further increase in luminance and a further decrease in manufacturing cost. To satisfy such demands, great efforts have been made to study several subjects involving the film thickness of the epitaxial layer, the carrier density or concentration, the crystal growth temperature settings, and other factors. Unfortunately, no efforts have been reported as being successful in demonstrating significant advantages leading to accomplishment of further improvements luminance at least at present.
For these reasons, it still remains difficult to meet luminance specifications as demanded, which in turn makes it difficult to provide an improvement in the manufacturing yield, while reducing the costs therefor.
In view of the foregoing, it may be appreciated by those skilled in the semiconductor art that there remains an unmet need for an epitaxial wafer capable of offering highly enhanced luminance with increased stability and reliability, along with an improved manufacturing method, as well as a light-emitting diode using the same.